1. Field
Inventive concepts generally relate to vertical memory devices, and more particularly, inventive concepts relate to vertical non-volatile memory devices including vertical channels.
2. Description of Related Art
When a VNAND flash memory device is fabricated, an insulation layer and a sacrificial layer may be alternately and repeatedly formed on a substrate, channel holes may be formed through the insulation layers and the sacrificial layers to expose upper surfaces of the substrate, respectively, and channels may be formed in the channel holes, respectively. The channels may contact the upper surfaces of the substrate to be electrically connected thereto. However, as the numbers of the insulation layer and the sacrificial layer stacked on the substrate increase and the sizes of the channel holes decrease, the channel holes may not expose the upper surfaces of the substrate, and thus the channels in the channel holes may not contact the upper surfaces of the channels, which may generate the electrical failure.